Food and Inflammatory Bowel Diseases: A scoping review on the impact of food on patients’ psychosocial quality of life

Abstract Growing bodies of literature show that a controlled diet is important in controlling the symptoms of Inflammatory Bowel Diseases (IBD). This leads patients to avoid foods considered potentially harmful. However, food is not just a nutrient but entails a series of hedonistic, cultural and social values. Thus, there is the concern that having to renounce certain foods might exert an impact on patients’ psychosocial quality of life, particularly in younger patients. The aim of this paper is to review the existing literature to address which aspects of the patients’ quality of life are affected by food restrictions. A scoping review was carried out. Five different databases were searched in January 2021. Retrieved papers were then screened to only include the relevant studies. Data were extracted and the main results of the studies were charted. A thematic analysis was carried out on the main results to identify the areas of psychosocial quality of life more often impacted by the food restrictions. From the initially identified 1967 unique entries, 14 studies were included. Results show that the perceived importance of food in controlling symptoms is confirmed by patients’ accounts. The most common strategy adopted was, thus, the avoidance of trigger foods. The thematic analysis revealed three domains that are impacted by these restrictions: psychological quality of life, social life, family sphere. This study highlights the impact that food restrictions exert on IBD patients’ quality of life, and warrants further studies to fill existing gaps, in particular regarding younger patients.


| INTRODUC TI ON
Inflammatory Bowel Diseases (IBD) are a group of chronic conditions affecting the gastrointestinal system. These diseases include patients affected by Crohn's Disease (CD) and Ulcerative Colitis (UC), as well as a minority of patients with Indeterminate Colitis (IC). These diseases cause a variety of symptoms, even though the severity and frequency of symptoms vary across individuals and in time, and can exert a strong impact on patients' quality of life. A recent review found that the highest reported prevalence and incidence of IBD were in European countries and in North America (Ng et al., 2017), even though since 1990 the incidence has been rising even in other continents, as industrialisation increased. Indeed, in 2008 the total economic burden of Crohn's Disease alone has been estimated at 10.9-15.5 billion dollars in the US, and between 2.1-16.7 billion euros in Europe (Yu et al., 2008). The relevance of these diseases for public health led to growing bodies of research focused on identifying the underlying causes that lead to a worsening in the frequency and severity of IBD patients' symptoms: among the various factors that might impact patients' symptoms, several studies highlighted the role of food and diet (Hou et al., 2014;Kinsey & Burden, 2016;Mehrabani et al., 2017). Indeed, the management of IBD symptoms through the implementation of dietary therapies aimed at modulating the intestinal microbiome is becoming a rather common method (Green et al., 2019). Patients themselves seem to frequently report an association between food and symptoms (Cohen et al., 2013). Nevertheless, even though the implementation of diets and food restrictions might help the patients to relieve their symptoms, this might actually come to a cost: from a psychological perspective, food is not only a nutrient but has several implications for people's identity and social life (Fischler, 1988;Lupton, 1994), though more marked in certain cultures (Rozin, 2005). Eating, indeed, is a fundamental part of our lives not only because it allows us to introduce nutrients and sustain our bodies, but also determines our own cultural identity ('Tell me what you eat, and I will tell you who you are') and is oftentimes a central activity in many important gatherings (Caplan, 1997). Thus, the dietary restrictions imposed by IBD might impact patients' possibility to both enjoy food and the social dimension it entails. This might be particularly relevant and worrying for younger patients (children and adolescents), as the potentially impoverished social life might compromise their psychosocial development; additionally, the very fact that they cannot behave (in relationships to food) like their peers might pose a threat to their own self-representation and self-esteem.
Thus, it is important to assess the impact that dietary restrictions might exert on IBD patients' quality of life and psychosocial wellbeing, particularly regarding younger patients, as this will allow to highlight potential sources of social and psychological distress and ultimately address the more critical areas to reduce patients' burden and to sustain their engagement in self-management.
The aim of the present paper is to map the scientific literature in order to map the existing evidence regarding the aspects of food that impact on the psychosocial wellbeing and the quality of life of patients with Inflammatory Bowel Disease.

| MATERIAL S AND ME THODS
In order to answer our research question, we conducted a scoping review, as defined by Armstrong et al. (2011). We preferred a scoping review instead of a systematic review as this is a type of literature review that allows a broader exploration of a certain topic of interest, and a less focused research question. Since we were interested in exploring the 'state of art' of the knowledge regarding how food restrictions and diets in IBD impact on the psychosocial wellbeing and the quality of life of patients, we decided that a scoping review was preferable.
To carry out our study in a rigorous, though flexible, way, we referred to a framework describing a 4-step process (Arksey & O'Malley, 2005): 1. identification of the possibly relevant studies by consulting a selection of the most relevant scientific citation databases; 2. selection of the potentially relevant studies by screening the titles and abstracts of the candidate articles identified in the databases; 3. data extraction and analysis from the eligible papers, and finally.
4. data charting and report.

| Identification of the possibly relevant studies
To identify all the potentially relevant articles to be included in our review, we interrogated the most important scientific databases in the medical and psychological field, namely: Scopus, Web of Science Core Collection, Pubmed, EBSCO_ Cochrane Central Register of Controlled Trials, and PsycINFO. The search was conducted on January 7, 2021, including only articles written in English. The research string was composed of three main queries, each composed of different synonyms (connected with 'OR'), and queries were connected to each other with 'AND' connectors. The three queries regarded, respectively: 'Inflammatory Bowel Disease', 'Food', and 'psychosocial wellbeing'. All the identified studies were then imported into a reference manager (Mendeley) and checked for duplicates.

What is known about this topic?
• Food is a known an important factor in determining IBD symptoms; • Patients with Inflammatory Bowel Diseases have to avoid certain foods which they believe could worsen their symptoms; • Little guidance is provided in helping patients understand which foods should be avoided.

What this paper adds?
• The psychosocial consequences of food restrictions have been investigated by a number of studies, both qualitative and quantitative; • The necessity to control diet and avoid certain foods exerts an impact on three different aspects of patients' lives: personal and psychological wellbeing, social life, and family sphere; • Several gaps exist however regarding the psychosocial impact of food restriction on younger patients.

| Screening and selection of relevant studies
The identified articles were then screened applying the following inclusion/exclusion criteria to the title and abstract of each publication; to be included, the article had to: 1) discuss the perception of the disease-food relationship in IBD patients, its psychosocial outcomes, and the quality of life derived from such relationship (clinical trials and publications that evaluated specific dietary or medical treatments efficacy, and articles that considered merely the nutrients and chemical characteristics of food, were excluded); 2) be in English and available; 3) be an original article (non-peer-reviewed articles, opinions, letters and reviews were excluded).
Two researchers of the team (LP and PF) screened the identified articles by reading titles and abstracts. Conflicts regarding inclusion or exclusion were resolved by consensus.

| Data extraction, collation and analysis
From the included studies we extracted three types of data: 1. Bibliometric data regarding the paper (reference, year of publication, journal and subject area of the journal); 2. Methodological data (quantitative or qualitative research, tools used, sample characteristics, nationality); 3. Main results of the studies.
In particular, regarding the results of the included study, we conducted a qualitative thematic analysis to identify the main themes that emerged from qualitative studies and/or were investigated in the quantitative studies. Thus, results from the included studies are reported inside the specific categories that were identified in our thematic analysis. After the first screening (title & abstract), 14 articles were included as potentially relevant and screened in full text. 3 of these papers were then excluded as they did not match the inclusion criteria. However, 3 additional papers-which were not found by our research string but retrieved by the inspection of included papers' reference lists-were later included, as relevant. The total number of papers included for data extraction was then 14.

| Characteristics of the included studies
The bibliometric data and principal characteristics of the 14 articles included in the review are summarised in Table 1. The oldest included article that investigates the impact of food in IBD patients is that from Jowett and colleagues from 2004 (Jowett et al., 2004), while the most recent is from 2021 (Crooks et al., 2021 sciences area: in particular, 3 articles were published in journals focused on gastroenterology (Crooks et al., 2021;Palant et al., 2015;De Vries et al., 2019), and an additional two in journals specifically dedicated to IBD (Limdi et al., 2016;Zallot et al., 2013). The remaining articles are from journals dedicated to medicine in general, nursing, or quality of life.
Three articles that were included in the review featured a sample with both IBD and IBS (Inflammatory Bowel Syndrome) patients (Fletcher & Schneider, 2006;Guadagnoli et al., 2019;Schneider et al., 2009). We decided to include these studies too, as the authors one article focused on black and minority ethnic communities in the UK (Alexakis et al., 2015). Table 2 describes the included studies' methods and methodologies.

| Main results
The studies included in our literature review confirm that patients perceive the diet as an important element to control the disease.
Some studies reported that a large part of participants (31%-48%) believe that diet is a potential cause of their IBD (Crooks et al., 2021;Limdi et al., 2016), even though other studies reported lower percent- diet (Crooks et al., 2021). Zallot et al. found that only 25% of their sample maintained a normal diet during relapse; more than half of the participants followed a low-residue diet (Zallot et al., 2013).
Other strategies to prevent symptoms emerged from the interviews were changing food preparation making dishes easier to digest, replacing 'bad foods' with 'good foods', eating slowly and moderating the intake of certain products without complete exclusion (Czuber-Dochan et al., 2020;Fletcher & Schneider, 2006).
Regardless of this, there are some accounts of patients stating that they base their own food choices based solely on their preferences, regardless of the (foreseeable) consequence of having to go to the toilet more often, as they did not feel like they could deny themselves the pleasure of eating certain foods and they felt that eating 'normal' food and living as they did before the diagnosis made them feel more 'normal' (Czuber-Dochan et al., 2020;Palant et al., 2015;Schneider et al., 2009).
Our thematic analysis revealed that these implemented strategies, the perceived necessity to renounce certain food categories and the attention that patients need to pay to food preparation and intake impact on three different aspects of their quality of life: personal and psychological wellbeing, social life, and family sphere.

| Personal and psychological wellbeing
Even though avoiding trigger food seems to be a functional strategy to reduce the frequency of relapses and flares, in many studies emerged that patients also reported that having to pay a higher level of attention on food intake affects their own personal lives, as many of them reported having troubles in managing everyday activities, due to the need to adapt their diet to control IBD symptoms (Alexakis et al., 2015;Chuong et al., 2019;Czuber-Dochan et al., 2020;Palant et al., 2015); indeed, many patients reported having to carefully plan their daily activities (e.g. food shopping, food preparation) in advance. This careful planning is often time consuming (Czuber-Dochan et al., 2020), and the need to constantly pay attention and to restrain their food routine may actually lead to feelings of frustration, annoyance and, finally, distress (Czuber-Dochan et al., 2020). Indeed, a study showed that the number of different diets a participant was following negatively correlated with his/her food-related quality of life: this is worrying, as the same study observed that two IBD patients out of three were following at least a diet at the time of the study, and many of them were following multiple diets (Guadagnoli et al., 2019). In some cases, food restriction revealed a maladaptive strategy, leading to a continuous sense of fatigue and extreme weight loss (Czuber-Dochan et al., 2020).
Another aspect that seems to impact on patients' personal and psychological wellbeing is the uncertainty caused by the difficulty in finding trustable and reliable sources of information regarding food. Indeed, it seems that one of the most common ways to identify trigger foods is by experimenting, using a 'trial and error' process, and listening to one's own body (in both adult and paediatric patients) (Chuong et al., 2019;Czuber-Dochan et al., 2020). However, this uncertainty and the fact that restrictions and sacrifices do not always work, make some patients feel frustrated, irritated and doubtful, potentially causing non-adherence and a worsening in the symptoms due to a lack of control of the diet (Czuber-Dochan et al., 2020;Palant et al., 2015). In particular, the participants in the study from Chuong and colleagues stated that the individuation of trigger foods is generally perceived as a personal experience and the list of these foods or food categories varied widely between young participants (Chuong et al., 2019). Indeed, personal experience seems to be one of the most common sources of information that patients need to rely on regarding nutrition and diet (Limdi et al., 2016;De Vries et al., 2019); in particular, in the study from Limdi and colleagues showed that half of their participants never received any nutritional advice (Limdi et al., 2016). This trend seems different for paediatric patients: one study indeed reported that almost all parents of children with IBD (91%) had received nutritional instructions and were more likely to rely on advice given by doctors (74%) and dieticians (70%), but many of them also admitted to search  Parents of children with a longer history of the illness indicated more frequently that food habits could cause their child's illness and parents of older children expressed greater fear that food can trigger an IBD flare. Among foods that children with IBD avoided were fast food (83%), soft cheeses (83%), vegetable vinegar pickles (83%), hot spices and spicy foods (82%), and carbonated and noncarbonated soft drinks (79%).
Parents of the children with a longer history of the illness more frequently admitted that their child shared the same menu as the other members of the family. In the opinion of 44% parents, the disease was the reason why the child feared or refused outdoor dining, with girls avoiding outdoor dining more often than boys. More than half of parents thought that children with IBD required care from a dietician and claimed that nutritional advice from a registered dietician was easily available. Almost all responders received nutritional instruction.
As a source of knowledge about diet, parents most often mentioned the doctor (74.3%) and/or dietician (70.1%), but they also sought information from nonprofessional sources (84.7%). Parents of children who suffered from IBD for a shorter period of time more often believed that children currently derive less pleasure from eating than before the illness. 1/3 of all participants believed that their children avoided some products they like because of fear of exacerbating the disease. 65% of respondents agreed that their child avoided foods they really liked: mainly fried dishes, sweets, fast food, milk and any milk products, and salty snacks. et al., 2020); while the majority of participants in a second study reported that they had to find out for themselves which dietary habits suited them the best, and that they received this very same advice from their own healthcare providers: not having access to a reliable source of information, and having instead to rely on try-and-error strategies, was however reported as a source of uncertainty and frustration (Palant et al., 2015).
Finally, the restrictions to the diet also impact on the 'pleasure of eating' that IBD patients experience. Only three quantitative studies investigated how IBD influenced the appetite and the pleasure of eating, but in these studies about half the adult participants (45%-66%) stated that the disease affected their appetite and their pleasure of eating and that they forced to deprive themselves of foods they really like in order to prevent relapse (Limdi et al., 2016;Marsh et al., 2019;Zallot et al., 2013). Authors found that appetite decreased during relapse, compared to remission; furthermore, the loss of pleasure and appetite was more evident in CD patients (87%), compared to UC patients (66%) (Limdi et al., 2016). Parents also reported negative effects of the disease on the enjoyment of food of their children with IBD (Pituch-Zdanowska et al., 2019). Food avoidance is perceived as a sacrifice also by paediatric patients. One study reported that one parent out of three believes that their children are avoiding some dietary products they really like because of the fear of exacerbation of symptoms, and parents of children with a shorter history of IBD tended more often to believe that their child derives less pleasure from food than before the onset of the disease. The products identified by parents as more 'painful to avoid', precisely because are usually the ones preferred by young patients, are fried dishes, sweets, fast food, milk and dairy products, and salty snacks.

| Social life
The need to avoid certain foods and to pay attention to food intake not only affects people's personal life and their psychological wellbeing but also has an impact on their social lives. For instance, one study reported that 44% of the interviewed parents of IBD patients consider the disease and the risk of flares as the main reason why their children avoid eating out; in particular, girls tend to refuse outdoor dining more often than boys (Pituch-Zdanowska et al., 2019). This might be exacerbated in those ethnic communities where sharing food has a stronger cultural significance: many interviewed patients reported having to renounce to participate in ceremonies and social events where food had a cultural relevance (Alexakis et al., 2015).
This is not only true for young patients, but also for adults, as different studies highlighted how the work environment and social events can create important challenges for people with IBD (Alexakis et al., 2015;Czuber-Dochan et al., 2020;Palant et al., 2015): for instance, some patients felt they had to control their disease by preparing their own lunch at home, by eating less or by directly avoiding eating when with their colleagues (Czuber-Dochan et al., 2020). The fact that patients need to eat at very well-regulated times with wellregulated portion sizes also affects their possibility to enjoy a meal out of home (De Vries et al., 2019). It has been reported that almost one patient out of four (21%-23%) refuses dining out of home in order to prevent relapses (Crooks et al., 2021;Limdi et al., 2016;Zallot et al., 2013).

| Family sphere
Finally, the need for a specific diet also impacts patients' family lives.
Regarding young patients, it has been reported that some parents, or whole families, adapted to their child's diets, thus renouncing the same foods that are potentially harmful to the patients themselves, or they might prepare separate dishes, but often these are only slightly different, in this way the patient would have the perception to eat 'the same thing' as the other members of the family (Chuong et al., 2019). The dietary practices and restrictions of the young patients seem to be considered very important by parents of paediatric patients: in a qualitative study (Chuong et al., 2019), some of the parents of children with IBD stated that they tried to maintain a 'normal' routine of food practices for their family, while also supporting their children's needs due to their IBD: indeed, many parents interviewed reported being careful during grocery and buying mainly products they considered healthy.
On the other hand, in other studies, between 19% and 28% of adult patients declared that they do not generally share the same menu as the other members of the family, and have a tendency to cook and eat different meals, even though this was sometimes perceived as stressful (Czuber-Dochan et al., 2020;Palant et al., 2015;De Vries et al., 2019). In one qualitative account, this was reported to be actually coupled with the sense of guilt from the young participants, as they reported feeling like a burden for their own families due to the special effort required to accommodate their needs (Alexakis et al., 2015).

| DISCUSS ION
The role of nutrition in determining chronic diseases evolution is  and fatty food, raw vegetables, dairy products, and food with a high content in fibres overall are oftentimes discouraged (Hou et al., 2014). Another source of distress (indirectly) related to food for IBD patients is the source of information: several studies report that patients, in order to develop their 'knowledge' and expertise of the foods they need to avoid, have to mostly rely on personal experience, trial and error, and sometimes even of potentially untrustful sources of information such as the web (Guadagnoli et al., 2019;Limdi et al., 2016;Pituch-Zdanowska et al., 2019;De Vries et al., 2019).
The anticipatory fear of incurring in symptoms related to food consumption, the sense of losing control over one's own nutrition and quality of life together with the experience of social isolation tend to have a negative impact on the psychological wellbeing of patients: many patients feel frustrated and annoyed by having to plan ahead due to their peculiar food routines, which might cause non-adherence and a worsening of symptoms (Czuber-Dochan et al., 2020;Palant et al., 2015).

| Limits
This study has some limitations. First and foremost, only articles written in English and retrievable by the authors were included in the screening process which might have led to the exclusion of some potentially relevant studies. Furthermore, only a selection of scientific databases was included in the search strategy, potentially limiting the number of articles retrieved. Finally, this is a review with a mostly descriptive purpose, as given the nature of the data it was not possible to do a meta-analysis. This clearly limits the extent of the conclusions that can be drawn, and the data that were collected could be biased due to their nature (as they are retrieved mostly from patients' perspectives and interviews). Moreover, given the nature of the scoping reviews, there are some limitations to this methodology: this study only summarises and describes significative results from quantitative (and qualitative) studies, thus reporting a potentially biased account of evidence. Readers should be aware of this possible bias in evidence selection. Nevertheless, scoping reviews allow a flexible summarisation of the 'state of art' of a field, have the potential to highlight gaps in the scientific literature regarding a certain topic, and are particularly appropriate in addressing broad research questions like the one presented in this paper (Arksey & O'Malley, 2005).

ACK N OWLED G EM ENTS
The authors would like to acknowledge AMICI Onlus for their sup-